Phytochemical profiling of Curcuma kwangsiensis rhizome extract, and identification of labdane diterpenoids as positive GABAA receptor modulators.

An ethyl acetate extract of Curcuma kwangsiensis S.G. Lee & C.

GABAA receptor modulation by piperine and a non-TRPV1 activating derivative.

The action of piperine (the pungent component of pepper) and its derivative SCT-66 ((2E,4E)-5-(1,3-benzodioxol-5-yl))-N,N-diisobutyl-2,4-pentadienamide) on different gamma-aminobutyric acid (GABA) type A (GABA(A)) receptors, transient-receptor-potential-vanilloid-1 (TRPV1) receptors and behavioural effects were investigated. GABA(A) receptor subtypes and TRPV1 receptors were expressed in Xenopus laevis oocytes. Modulation of GABA-induced chloride currents (I(GABA)) by piperine and SCT-66 and activation of TRPV1 was studied using the two-microelectrode-voltage-clamp technique and fast perfusion.

Abietane diterpenoids from Salvia sahendica--antiprotozoal activity and determination of their absolute configurations.

In a screening of Iranian plants for antiprotozoal activity, an n-hexane extract of the roots of Salvia sahendica potently inhibited the growth of Plasmodium falciparum K1 strain. Subsequent HPLC-based activity profiling led to the identification of seven known and one new abietane-type diterpenoid. Structure elucidation was achieved by analysis of spectroscopic data including 1D and 2D NMR.

HPLC-based activity profiling--discovery of sanggenons as GABAA receptor modulators in the traditional Chinese drug Sang bai pi (Morus alba root bark).

EtOAc extracts from two batches of Morus alba root bark (Sang bai pi) potentiated γ-aminobutyric acid (GABA)-induced chloride influx in Xenopus oocytes, which transiently expressed GABA (A) receptors of the subunit composition α₁β₂γ(2S). With the aid of HPLC-based activity profiling of the extract from the first batch, activity was traced to a peak subsequently identified as sanggenon G (3). The second batch had a different phytochemical profile, and HPLC-based activity profiling led to the identification of sanggenon C (4) and a stereoisomer of sanggenon D (2) as positive GABA (A) receptor modulators.

Discovery of GABA(A) receptor modulator aristolactone in a commercial sample of the Chinese herbal drug "Chaihu" (Bupleurum chinense roots) unravels adulteration by nephrotoxic Aristolochia manshuriensis roots.

In a two-microelectrode voltage clamp assay using Xenopus laevis oocytes, a petroleum ether extract prepared from a commercial sample of the traditional Chinese herbal drug labelled as " Chaihu" (Bupleurum chinense DC. roots) enhanced the I(GABA) by 156 % ± 22 % when tested at 100 µg/mL. By means of HPLC-based activity profiling combined with high-resolution LC-MS and microprobe NMR, the germacranolide aristolactone was identified as one of the main active compounds (EC₅₀ 56.

Identification of GABA A receptor modulators in Kadsura longipedunculata and assignment of absolute configurations by quantum-chemical ECD calculations.

A petroleum ether extract of Kadsura longipedunculata enhanced the GABA-induced chloride current (I(GABA)) by 122.5±0.3% (n=2) when tested at 100 μg/ml in Xenopuslaevis oocytes expressing GABA A receptors (α(1)β(2)γ(2S) subtype) in two-microelectrode voltage clamp measurements.

Identification and characterization of GABA(A) receptor modulatory diterpenes from Biota orientalis that decrease locomotor activity in mice.

An ethyl acetate extract of Biota orientalis leaves potentiated GABA-induced control current by 92.6% ± 22.5% when tested at 100 μg/mL in Xenopus laevis oocytes expressing GABA(A) receptors (α₁β₂γ(2S) subtype) in two-microelectrode voltage clamp measurements.

Positive GABA(A) receptor modulators from Acorus calamus and structural analysis of (+)-dioxosarcoguaiacol by 1D and 2D NMR and molecular modeling.

In a two-microelectrode voltage clamp with Xenopus laevis oocytes, a petroleum ether extract of Acorus calamus rhizomes enhanced the GABA-induced chloride current through GABA(A) receptors of the α₁β₂γ(2S) subtype by 277% ± 9.7% (100 μg/mL). β-Asarone (1), (+)-dioxosarcoguaiacol (2), (+)-shyobunone (3), and (+)-preisocalamenediol (4) were subsequently identified as main active principles through HPLC-based activity profiling and targeted isolation.

HPLC-based activity profiling of Angelica pubescens roots for new positive GABAA receptor modulators in Xenopus oocytes.

A petroleum ether extract of the traditional Chinese herbal drug Duhuo (roots of Angelica pubescens Maxim. f. biserrata Shan et Yuan), showed significant activity in a functional two-microelectrode voltage clamp assay with Xenopus oocytes which expressed recombinant γ-aminobutyric acid type A (GABA(A)) receptors of the subtype α(1)β(2)γ(2S).

HPLC-based activity profiling for GABA(A) receptor modulators: a new dihydroisocoumarin from Haloxylon scoparium.

A new dihydroisocoumarin was isolated from a dichloromethane extract of Haloxylon scoparium with the aid of a functional assay with Xenopus oocytes transiently expressing GABA(A) receptors of defined subunit composition (alpha(1)beta(2)gamma(2S)). Compound 1 induced a maximum potentiation of the chloride currents by 144.6 +/- 35.

HPLC-based activity profiling: discovery of piperine as a positive GABA(A) receptor modulator targeting a benzodiazepine-independent binding site.

A plant extract library was screened for GABA(A) receptor activity making use of a two-microelectrode voltage clamp assay on Xenopus laevis oocytes. An ethyl acetate extract of black pepper fruits [Piper nigrum L. (Piperaceae) 100 microg/mL] potentiated GABA-induced chloride currents through GABA(A) receptors (composed of alpha(1), beta(2), and gamma(2S) subunits) by 169.

Quantitative analysis of anti-inflammatory and radical scavenging triterpenoid esters in evening primrose seeds.

Lipophilic triterpenoidal esters with radical scavenging and cyclooxygenase inhibitory properties were recently found in cold-pressed, nonraffinated evening primrose oil (EPO). A quantitative assay for the analysis of 3-O-trans-caffeoyl derivatives of betulinic, morolic, and oleanolic acid in evening primrose seeds was developed and validated. Extraction efficiency >99% was achieved by means of pressurized liquid extraction with two extraction cycles and 80% (v/v) ethanol at 120 degrees C.